1. Field of the Invention
The present invention relates to an ozonizer and more particularly to an ozonizer for obtaining ozonized water by means of an electrolysis (electrolytic process) to obtain ozone-dissolved water in which ozone is dissolved.
2. Prior Art
As conventional methods of obtaining ozonized water, a discharge method and an electrolytic method are generally known, wherein the former method has steps of an oxygen gas (or, in some cases an air) is passed through silent discharge electrolysis to produce an ozone gas of a high concentration and subjecting this ozone gas to be contacted with water to dissolve the ozone in the water. However, the discharge method described above requires a large scale equipment and, moreover, involves some dangers in leakage of ozone gas because an ozone gas of a high concentration is once generated before it is dissolved in the water. Further, there are cases that undissolved ozone of a vapor phase is remained in the water and then discharged to the atmosphere, with the result of problems of malodor or offensive odor of ozone.
With respect to the ozonizer of the latter method, that is, electrolytic method, water is electrolyzed and, since ozone is mixed with an oxygen which is generated at an anode (positive) electrode side, the ozone is directly dissolved in the water of the electrolysis. In the conventional electrolytic ozonizer, a thin ion exchange membrane is disposed between the two electrodes for electrolytic process to effectuate the electrolytic process, so that an ozone concentration becomes high. In this method, it is known that an application of a platinum, which inherently has a catalytic effect, as an anode electrode will increase an efficiency of ozone generation.
Further, it is known that if the electrodes for the electrolytic process are formed into a wire netting (or wire screen) structure, a further efficient electrolytic operation is expected and, therefore, platinum electrodes of a wire netting structure have been disposed on both sides of a plate-like ion exchange membrane in an overlapping relation so that the water flows along the anode (positive) electrode side such that the water contacts both the anode electrode and an exposed surface of the ion exchange membrane. This method is known to be the most efficient method of the ozonizer.
In the ozonizer of the electrolytic process described above, the generated ozone is immediately dissolved in the water and, therefore, there is less danger of ozone leakage and, in addition, this type of ozonizer has an advantage that it can be formed in a smaller scale. However, there are other problems that it requires a relatively large ion exchange membrane having an area of 30 cm.sup.2 or more and still has a problem of a large-scale configuration, and requires an extremely high dimensional accuracy in production because, unless the electrode is constantly pressure-held on the ion exchange membrane, a constant efficiency of ozone generation is not realized. In other words, in the conventional ozonizer of a planar type, an accurate and high machinability and preparation of special materials of plastic deformation for electrodes or an electric collector are required for the purpose of obtaining a constant pressure-contact of the electrodes against the ion exchange membrane.
Further, when the electrolytic ozonizer is used, fine bubble-like ozone is suspended and remained in the ozone water, and the ozone water immediately after obtained has malodor of ozone and, therefore, there is a problem that such an electrolytic ozonizer will not suitable for use in a closed room such as a clear room, a medical consulting room, etc.